The palmitoyl derivative of the linear polypeptide of poly-(L-Glu-L-Lys-L-Phe)n (GLphi) can be coupled to spleen cells directly. The intravenous administration of 2 X 10(5)--3 X 10(7) GLphi-coupled syngeneic spleen cells induces GL-phi-specific suppressor T cells in C57BL/6 nonresponder mice. The suppression is antigen specific and can be detected by the inhibition of the primary GLphi plaque-forming cell response to challenge with GLphi-fowl gamma globulin. The number of inducer cells required for suppression carry less than 0.1 microgram of antigen. Spleen cells from tolerized mice can transfer suppression to normal syngeneic recipients. The suppression is cyclophosphamide sensitive and the suppressor cells bear the Thy 1.2 marker. This method of inducing antigen-specific suppressor cells may be generally applicable to other antigen systems.